Submission #859381

#	Time	Username	Problem	Language	Result	Execution time	Memory
859381		maks007	Graph (BOI20_graph)	C++14	0 / 100	0 ms	348 KiB

Graph

#include "bits/stdc++.h"
 
using namespace std;
 
#define int long long
 
vector <vector <pair <int,double>>> g;
vector <double> used;
vector <int> comp;

void dfs(int v) {
	used[v] = 1;
	for(auto [i, j] : g[v]) {
		if(used[i] == 1e9) dfs(i);
	}
}

void get_comps() {
	for(int i = 0; i < used.size(); i ++) {
		if(used[i] == 1e9) {
			dfs(i);
			comp.push_back(i);
		}
	}
}

int check(int v) {
	int f = 1;
	for(auto [i, j] : g[v]) {
		if(used[i] == 1e9) {
			used[i] = j - used[v];
			f = min(f, check(i));
		}else {
			if(used[i] + used[v] != j) f = 0;
		}
	}
	return f;
}

vector <pair <int,double>> rec(int v) {
	double mn = 1e9;
	vector <pair <int,double>> ans;
	for(double val = -2; val <= 2; val += 0.1) {
		for(auto &j : used) j = 1e9;
		used[v] = val;
		if(check(v)) {
			double cnt = 0;
			for(auto &j : used) {
				if(j == 1e9) continue;
				cnt += fabs(j);
			}
			if(cnt <= mn) {
				mn = cnt;
				for(int j = 0; j < used.size(); j ++) {
					if(used[j] == 1e9) continue;
					ans.push_back({j, used[j]});
				}
			}
		}
	}
	if(mn == 1e9) {
		cout << "NO\n";
		exit(0);
	}
	return ans;
}

signed main () {
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	int n, m;
	cin >> n >> m;
	g.resize(n);
	used.resize(n, 1e9);

	for(int i = 0; i < m; i ++) {
		int u, v;
		cin >> u >> v;
		u --, v --;
		double w;
		cin >> w;
		g[u].push_back({v, w});
		g[v].push_back({u, w});
	}

	get_comps();
	for(auto &j : used) j = 1e9;
	vector <vector <pair <int,double>>> res;
	for(auto i : comp) {
		res.push_back(rec(i));
	}
	cout << "YES\n";
	vector <double> ans(n);
	for(auto i : res) {
		for(auto j : i) ans[j.first] = j.second;
	}
	for(auto i : ans) cout << i << " ";
	return 0;
}

Compilation message (stderr)

Graph.cpp: In function 'void dfs(long long int)':
Graph.cpp:13:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   13 |  for(auto [i, j] : g[v]) {
      |           ^
Graph.cpp: In function 'void get_comps()':
Graph.cpp:19:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<double>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |  for(int i = 0; i < used.size(); i ++) {
      |                 ~~^~~~~~~~~~~~~
Graph.cpp: In function 'long long int check(long long int)':
Graph.cpp:29:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   29 |  for(auto [i, j] : g[v]) {
      |           ^
Graph.cpp: In function 'std::vector<std::pair<long long int, double> > rec(long long int)':
Graph.cpp:54:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<double>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |     for(int j = 0; j < used.size(); j ++) {
      |                    ~~^~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 12
• Subtask 3: 0 / 17
• Subtask 4: 0 / 24
• Subtask 5: 0 / 42